This invention generally relates to the field of automatic occupancy sensing systems for use in vehicle seats. More specifically, it relates to methods and apparatus employed to produce data corresponding to the weight and the weight distribution or compression pattern of the seat occupant and to gather and interpret the data by a computerized system.
The automotive airbag was designed to provide protection to passengers during vehicle collisions. Traditionally, the passenger-side airbag has been permanently ready to deploy in case of a collision involving front or side impact. However concerns about the impact on children and small adults have led to developments that may allow the driver or passenger to disengage the airbag by way of an on/off toggle or key switch. Because of its nature, i.e. operator/manual control, there is a chance of operator error by forgetting or neglecting to actuate the switch to the setting appropriate to the type of person occupying the passenger seat. The US National Highway Transportation and Safety Administration NHTSA issued a Federal Motor Vehicle Safety Standard FMVSS-208, to combat the danger due to operator error and for other reasons. FMVSS-208 requires that 25% of all passenger vehicles produced in the United States, during and after 2004, have an automatic airbag deployment suppression system. The automatic airbag deployment suppression system must determine the mode of airbag deployment to be either fully enabled or fully suppressed based on the current occupant of the seat. By 2008, the automatic airbag deployment suppression system must also control the rate and percentage of airbag deployment depending on the current occupant of the passenger seat and be present in 100% of all new vehicles produced or sold in the United States.
Several patents cited with this application illustrate attempts by others to sense whether the occupant in the passenger seat is an adult above a certain weight or not and provide a deactivation signal to the air bag deployment control if not. Many of the prior patents show the use of multiple sensors in multiple locations to determine such things as whether the occupant is a human being, the location of the face and more elaborate determinations. Many systems found in the prior art are complex and expensive to fabricate, calibrate and maintain.